Aiuto con select sum

[idro]

no quello era l'errore io ho questo codice:

$this->db->select('*'); 
      $this->db->where('xx_id', $param5); 
      $query1 = $this->db->get($this->session->userdata('spazio').'_zona_utenti'); 
       if ($query1->num_rows() > 0) 
      {  
      $row = $query1->row_array(); 
      $rs = $this->db->query('SELECT SUM(totalnumber) FROM `'.$this->session->userdata('spazio').'_users` WHERE id='.$row['user_id'].''); 
      } 
// PHP 4 syntax 
$row = $rs->row(); 
//echo $row->points; 

// PHP 5 syntax 
//$query2->row()->points;      
     echo number_format($row->totalnumber);